Feeding mechanism



June 13, 1939. G BENJAMIN 2,161,892

FEEDING MECHANISM Original Filed April 6, 1932 6 Sheets-Sheet l 11172 636217221121 1; /& ,4 M

June 13, 1939. M. G. BENJAMIN 2,161,892

FEEDING MECHANISM Original Filed April 6, 1932 6 Sheets-Sheet 2 is yrw'll GBqzjm/zz'zz 29M/Y M Gum/mm M. G. BENJAMIN 2,161,892

FEEDING MECHANISM June 13, 1939.

Original Filed April 6, 1932 6 Sheets-Sheet 3 Ivvswrae.

76W??? lleryamz'n June 13, 1939. G, BENJAMIN 2,161,892

FEEDING MECHANI SM Original Filed April 6 1932 6 Sheets-Sheet 4 Hie/W72 GBeZq'amm June 13, 1939. I M. are NJAMRN EMdPllllyfm e New-W572 GBmy'amin FEEDING MECHANISM Original Filed April 6, 1932 6 Sheets-Sheet 6 Inventor 2131:1272 GBerg'amim g M Patented June 13, 1939 FEEDING LECHANISM Merrill G. Benjamin, Alhambra, Calif., assignor to Minneapolis-Honeywell Regulator Company,

Minneapolis, Minn., ware a corporation of Dela- Original application April 6, 1932, Serial No.

Divided and this application November 20, 1935, Serial No. 50,689

15 Claims.

This invention relates to an apparatus for feeding material into a receiver, chamber or the like at a desired predetermined rate, whereby it may be used for mixing materials in, or fed to,

such receiver in desired proportions, or maintaining therein a substantially predetermined supply of the material where such material is being removed or discharged from the receiver or consumed therein. 1

In the illustrated application of the invention, the receiver constitutes the fire box of a furnace or other heating apparatus and the material to be fed or delivered thereto comprises solid combustible fuel, for example, coal or coke (or a mixture thereof) in powdered or other forms, (buckwheat, barley, nut or larger sizes) as desired; and in such application of the invention, it includes a control mechanism responsive to combustion conditions for controlling and maintaining adequate combustion conditions in the furnace.

This application forms a division of my copending application, Serial No. 603,653, filed April 6, 1932.

An object of the invention is to provide an improved mechanism for feeding fuel to a the bed' at a rate substantially equal to the rate of combustion therein, whereby resulting gases are consumed or burned in the fire box and heat losses are avoided.

Another object of the invention is to provide an improved fuel feeding mechanism adaptable to manually fired heating apparatus and capable of so placing the fuel in the fire box that a maximum area of contact between the fire bed and 5 heat absorbing surfaces of the fire box is obtained.

Another object of the invention is to provide a fuel feeding mechanism and to combine therewith an improved means for distributing the fuel to or upon the fire bed and for causing turbulence of the gases and air in the fire box, whereby oxygen is mixed with the gases and burned therewith and stratification of air and combustion gases in the'fire box is prevented.

Another object of the invention is to provide an improved apparatus of this character in which fuel may be fed to a fire box in small quantities in a substantially uniform manner.

[Another object of the invention'is to provide an improved feeding mechanism having related devices which insure substantially uniform feeding of the fuel with'out danger. of caking or clogging of the fuel affecting the operation of the mechanism.

A more specific object of the invention is to provide an improved mechanism for feeding fuel from a hopper to .a combustion chamber, such mechanism including a feed channel, one wall of which reciprocates relative to another wall of the channel and serves to feed the fuel forwardly and partially to support the fuel while being fed, whereby uniformity of feed and discharge of.

the fuel into the combustion chamber results.

Another object of the invention is to provide Another object of the invention is to provide a unitary mechanism for feeding fuel to a fire box of a heating apparatus and supply air thereto below the fuel bed, whereby a suflicient draft is insured and adequate combustion maintained to effect efiicient consumption of the fuel under varying temperature conditions.

A further object of the invention is to provide a portable, unitary fuel feeding and air supply mechanism readily adaptable to varying types of furnaces and other heating apparatus without alteration of the latter.

A still further object of the invention is to provide a fuel stoking mechanism having feed devices extending into the fire box of a heating apparatus and means for supplying air to the walls of said feed devices to prevent over-heating thereof without affecting fuel combustion in the box. I

'A still further object of the invention is to provide a fuel stoking mechanism having a control device therein subject to combustion conditions for controlling the operation of the fuel stoking mechanism. e

Other objects of the invention will be apparcut to those skilled in the art to which my inv'entionrelates, from the following description taken in connection with the accompanying drawings, wherein Figure 1 is a side elevational view of a structure embodying the instant invention shown in operative relationship with a heating apparatus, certain parts of the latter being shown in section and certain other parts being cut away.

Figure 2 is a front elevational view of the mechanism, certain parts thereof being broken away.

Figure 3 is a top plan view of the mechanism, certain detailed parts being omitted.

Figure 4 is a view along the line 4-4 of Figure 2 as viewed from the top, the fuel feeding device being omitted.

Figure 5 is an enlarged fragmentary sectional view showing details of construction taken along the line 55 of Figure 4 as viewed from the bottom.

Figure 6v is a continuation of Figure 5, the right-hand portions of the two figures forming a contiguous member.

Figure 6a is a sectional view along the line ill-6a of Figure 6 as viewed from the top.

Figure 7 is a fragmentary perspective view of the delivery end of the fuel feeding trough and feeding devices, parts thereof being broken away to facilitate the illustration.

Figure 7a is a detailed perspective view of one of the elements in the spout or trough and is taken along the line la -1a of Figure 7 looking in the direction of the arrows.

Figure 8 is an enlarged sectional view taken along the line 8-8 of Figure 3 as viewed from the top, certain parts thereof being omitted and certain other parts being cut away.

Figure 9 is a fragmentarysectional view taken along the line 99 of Figure 8 as viewed from the left.

Figure 9a is a sectional view on the line 9aF-9a of Figure 9 as viewed from the top.

Figure 9b is a fragmentary view of certain details of construction, parts thereof being broken away, and comprises a continuation in part of Figure 9 extending towards the right.

Figure 10 isa sectionalview on the line Iii-l of Figure 9 as viewed from the right.

Figure llis a fragmentary sectional view on the line ll-ll of Figure 2 as viewed at an angle from the upper left.

Figure 11a is a sectional view taken along line Ila-l la of Figure 11 as viewed fromthe right.

Figure 12 is a diagrammatic view of one form of circuit suitable for the control means for the mechanism of the instant invention.

Figure 13 is a view similar to Figure 7 but dis Y closing a modified form of construction.

Figure 13a is a fragmentary sectional view of Figure 14 is an enlarged sectional view on the line "-44 of Figure 13a as viewed from the left.

Ilia-46a. of Figure 16 as viewed from the right.

Figure 1'7 is, a front elevational view of a still further modification in form of the feeding devices, being a section along the line l'|l'I of Figure 17a as viewed from the right.

Figure 17a is a sectional view of the parts shown in Figure 1'7 and taken along the line l'lar'lla of Figure 17 as viewed from the right.

Figure 18 is a sectional view of a still further modification in form of the feeding devices.

In the drawings, l indicates as an entirety a heating apparatus which may comprise a hot water or steam boiler, but which is illustrated by way of example, in the form of a warm air furnace having a fire box 2; a grate 9, ash pit 4 and air drum 4a from which flues (only one being shown) lead to the areas (such as the rooms of a building) to be heated; the fire box 2 having a feed opening 1 and the ash pit 4 having an opening 8.

A support generally indicated at 9, is mounted on suitable rollers l0, which may be of the caster type. The support 9 preferably consists of a pair of inverted U-shaped members 9a formed of tubing, the open ends of which receive the shanks Ilia of the mountings for the rollers Ill. The shank for each roller mounting may be adjusted vertically in the adjacent tube and fixed in adjusted position by a set screw llib. The legs of the U-shaped members are bent laterally as shown in Fig. 3 to stabilize the mechanism. An angle plate II has a horizontal portion Ila. which is rigidly secured to U-members 9a, as by clips l2, such portion serving to hold U-members 9a in rigid, spaced relation. A locking device I3 is adapted to hold support 9 and the mechanism carried thereby in operative relation to the heating apparatus l, as shown in Fig. 1, the rollers l0 permitting the support to be readily rolled into and out of position and the locking device l3 serving to prevent it from moving away from the heating apparatus I due to any unevenness in the floor F or some other causes. Such locking device I3 is in the form of a prop, which eliminates the necessity of connecting the support to the heating apparatus l.

Locking device i3 is pivotally connected at its upper end to a U-clip M on the horizontal por- .tion Ila of the angle plate ii and adapted to engage the floor F at its opposite end, as shown in Fig. 1. Locking device l3 consists of two elements I31: and l3b, preferably adapted to telescope, one within the other, whereby locking device l3 may be lengthened or shortened to suit varying conditions, the elements'being fixed in adjusted relation by a set screw l5. Locking device l3 may be held in an inoperative position by a hook l5a secured to the underside of portion lla.

A spout i6 is connected at its inner end to a vertical portion lib of .the angle plate II and extends forwardly therefrom for projection through the fire box opening 1 into the fire box 2, as shown in Fig. 1. The spout I6 is formed of high heat resisting sheet metal. At its inner end the spout I6 is provided with flanges by which it is rigidly bolted or otherwise secured to the plate portion lib. The spout l5 forms an enclosed conduit for the fuel from a hopper ii to the space inwardly of the opening I within the furnace l and a support for the fuel feeding devices to which reference will later be made. The inner end of the spout l6 registers with an open-, ing formed in the portion llb through which the fuel is fed from the hopper ii. The spout I6 is preferably rectangular in cross section and comprises a bottom Ilia, sides llib and a top iBc, but the latter preferably terminates inwardly .of the outer 'or free end of the bottom and side walls forming the spout (see Fig. 3). The bottom, sides and top of the spout l6 form a support for an adjustable closure and shield l8, which is adapted to engage the walls of the opening I and close the space between these walls and the walls of the spout. In this connection it will be noted that when my mechanism is positioned (see Fig. 1), the door for the opening I is removed and the support 9 is positioned with the shield l8 in engagement with the walls 'of the opening 1, so that it becomes a door, with the spout l6 extending therethrough, to close the opening. The closure l8 comprises a relatively thick asbestos boardand extends downwardly below the opening to shield the operating mechanism and other parts from heat radiating from the furnace walls. The shield I8 is provided on its outer face with a plurality of angle strips l9 which slidably engage the walls of the spout so as to permit adjustment of the shield inwardly and outwardly, relative to the outer or delivery end of the spout. The strips l9 may be adjustably fixed to the spout in any desired manner.

When so fixed, the delivery end of the spout will be in the desired relation to the center of the fire box 2 when the support 9 is moved into position with the shield l8 against the walls of the opening I. I

A trough 20 extends from a point near the delivery .or outer end of the spout therethrough and the opening in the portion llb to the hopper H, the trough 20 being connected with the discharge opening of the latter and closed at its inner end by a wall 2| (Figs. 1, 2 and 3. The trough 20 comprises a bottom plate 22 having a horizontal portion 22a disposed in spaced relation to the bottom |6a of spout l6, upwardly inclined sides 22b, and an upper plate 23, preferably of W-shape in cross section, the lateral sides of which are parallel to and spot-welded to the sides 22b. The inner end of the plate 22 is connected to the wall 2| and its outer end is connected to a transverse upstanding wall 24 having a flange on which portion 22a rests, said flange being suitably secured to the bottom |6a of the spout l6; whereas the center part 23b of plate 23 extends from the wall 2| outwardly beyond the wall 24 (see Fig. '7) for a purpose later set forth. The lateral edge portions 26 of the sides 23a of the plate 23 are extended further, as shown at 22' to provide extended guides hereinafter referred to. The transverse wall 24 is cut away throughout its central portion, correspond ing to the cross section of the plate 22. The wall 24 serves to close the space between the plates 22, 23, and adjacent walls IBa, lBb, of the spout l6, to prevent in-flow of heat and gases into the spout and out-flow of air therefrom. The lateral longitudinal edges of the plate 23 are vbent inwardly, as shown at 26, at substantially right angles to the upwardly and outwardly inclined sides 23a and the free edges of the bent portions 26 are bent back thereon, as shown at 21, to form closed guides, for a purpose later set forth. Channel irons 28 are secured to the side walls I61) and form supports for the side portions of the sides 23a.

By forming the plate 23 into Wshaoe. it will be seen that I provide two parallel feeding channels 29, 30, for the fuel or material. leading from the hopper substantially to the discharge end of the spout, each having incl ned sides. and each closed along its bottom and connected together to form a closed space between their inner or adjoining sides. which space is utilized for the power operated elements to effect feed for the fuel. as will later appear. Each feed channel is thus formed of two walls which co-operate to support the fuel asit is fed from the hopper to the point of discharge. .One side of each channel 29, 30, forms a guideway and support for a reciprocatable member 3|. preferably extending from the wall 2| to the end of the spout I6, less the maximum travel of said member, whereby the fuel is progressively fed forwardly uniformly for discharge from the outer end of the spout l6. By mounting the reciprocating member on one wall of the channel, it partially supports the fuel during feed thereof. In the form of construction shown in Figs. 1, 3, 4, '7 and 8, reciprocatable members 3| are mounted on the outer sides 23a of the channels 29, 30, and each comprises a sheet metal strip having a width substantially equal tothe width of a side 23a of plate 23, and provided along its outer longitudinal edge with a flange 32 which slides in the guideway formed between the adjacent walls 26, 21. Each member 3| is provided with material advancing. elements 33 and the adjacent side 23b of the channel is provided with material retarding elements 33a. Each element 33, 33a, preferably comprises a transverse, up-standing rib, formed by offsetting the metal to form an active transverse face at substantially right angles to the surface of the metal, the rearward portion of the off-set metal section being inclined'inwardly and merging with the surface of the metal, so that the fuel is fed forwardly on the stationary device by the elements 33 on the reciprocatable members 3| without appreciable obstruction, but is held against rearward or retrograde movement during inward movement of the reciprocatable members 3| by the elements 33a. In this arrangement of relatively movable sides for each channel, uniform supply of the fuel in small quantities to the fire bed is insured in the operation of the reciprocatable members 3|, the effect of which is to provide an even and uniform active combustion in the fire bed of the furnace, in accordance with the operations of the mechanisms controlling such feeding mechanism (as later set forth), so that the resulting combustion consumes in the fire box substantially all of the resulting gases. Furthermore, in the arrangement described, the

reciprocatable members 3| co-act with the op-' posed walls 23b to keep the material concenthe material to gravitate in the channel while I being moved forwardly. In the preferred arrangement shown, each channel comprises a stationary inclined side and a reciprocatable inclined side, so that the fuel is supported substantially equally on both these'sides and accordingly there is a positive engagement between the reciprocatable member 3| and the fuel. As these sides extend continuously from end to end of the spout, the same movement is simultaneously imparted to all portions of the fuel between the hopper and discharge end of the spout. By reason of this arrangement and operation, the feed of the fuel is progressive from end to end of the spout and danger of portions of the fuel accumulating into piles or masses and being pushed laterally over the' sides of the channels or discharged as such into the fire box is substantially eliminated. Also, a more even control of the fire bed is insured and accumulation of unburned gases is prevented, irrespective of the rate of speed of,

fits into the guide-way and the latter is closed by the bent portion 21, fuel dust and fuel particles cannot lodge in between a reciprocatable member 3| and a side 23a and affect its operation.

The means for reciprocating the members 3| comprise the following:

An electric motor at is suitably fixed to the plate Ila. One end of the drive shaft 342) of the motor 34 extends into a casing 34a (see Fig. 9b) and is provided with a worm 35 which is in mesh with a worm gear 36 on a horizontal shaft 36a, said shaft being suitably supported in the casting 34a. The shaft 36a is provided with a worm 31 which" meshes with a worm gear 36 on a vertical shaft 36a, also suitably supported in the casing 34a, and carrying a crank 39, preferably comprising a cross member extending radially to either side of the shaft. The shaft 36a, in the preferred form of construction also drives a flexible shaft, as hereinafter set forth. A

bracket 46 is fixed to the wall Ilb (see Fig. 9) and supports a bearing 41 for a shaft 42 disposed substantially axially of the shaft 360. The shaft 42 carries on its upper end a crank 43 and on its lower end a cross member 44 extending radially of the shaft to opposite sides thereof, these parts being pinned to the shaft to prevent endwise movement thereof in its bearing 4|. The outer ends of the member '44 carry depending pins 45 disposed in the path of movement of the crank 39 and are engaged by the opposite end portions of the latter to rotate the shaft 42, these parts thereby serving as a flexible connection between the shafts 38a and 42. By preference, the pins 45 are provided with rollers to reduce friction between them and the crank 39 and such .rollers may be formed of rubber or provided with rubber peripheries to eliminate noise. A hollow bar generally indicated at 46, formed of sheet metal and preferably triangular in cross section, is slidably fitted within the space between the sides 23b of the plate 23 and bottom section 22a of the .plate 22, the outer end of the bar 46 being connected to the reciprocatable members 3|, as later set forth. A block 41 is fitted within the bar 46 near its inner end and fixed thereto by a plurality of countersunk screws 41a (see Figs. 9 and 10). The block 41 is formed with a horizontally disposed opening therethrough to accommodate a rod 49, which is free to rotate in the opening but is fixed to the block against relative endwise movement by washers engaging its opposite ends and held by cotter pins 49a or other suitable devices. The inner end of the rod 491s threaded through a pair of spaced nuts 50, 5|, disposed upon opposite sidesof the crank 43 and arranged -to be engaged by the latter as it revolves to effect reciprocation of the rod 49 and through it, reciprocation of the hollow bar 46. The threads on the rod 49 are right and left hand, so that by rotating the rod, the nuts 50, 5|, may be adjusted toward or away from each other, the effect of which is to increase or decrease the throw of the rod, in each revolution of the crank 43, within 'certain limits. The nuts 50, 5|, are shaped to loosely slide within the bar 46, but are held against rotation by the walls thereof. The crank 43 is preferably provided with a hardened steel roller 43a to engage the nuts 50, 5|, to reduce friction. The bottom l6a of the spout I6 is formed with an opening ,46 (see Figs. 3 and 4) and the bottom walls of the bar 46are cut away (see Fig. 9) to accommodate the crank Bar 46 is suitably connected to the reciprocatable members 3| and such securing means may be of the form now to be described. As better shown in Figure 7a, transvrese slits are cut into the bottom walls 46a. of bar 46 at a point spaced from their outer ends. The bottom por- .end portions of reciprocatable members tions 46a extending outwardly beyond these slits are then bent upwardly and outwardly into W- shape and in parallel relation with the ougelr Suitable spacers 52 are positioned between reciprocatable members 3| and upwardly and outwardly extending portions 46b and the parts spot-welded to maintain the samein related assembly. Spacers 52 are of slightly greater thickness than the outer side walls 23a of channels 29 and 30 and accordingly portions 46b of member 46 are positioned outwardly from walls 23a with respect to spout l6. Transverse slits previously referred to inwalls 46a of bar 46 are positioned at a point rearwardly of the free end of the walls 230 comprising the outer-. most portions of channels 29 and 30whereby; the portions 46b underly these latter walls, throughout the travel of the reciprocatable members 3| to prevent fuel from gravitating. into spout l6 to the rear of members 46b. Also;

by forming the bar 46 of triangular shape,

its top walls and the outer end portions of the members 3|. form c-ontinuations of the channels 29, 30, as the bar and members move outwardly and inwardly, to convey the material to the discharge end of the spout where it'gravitates to the fuel bed. The bar 46 is closed by a wall 46' disposed rearwardly of the sections 46b (see Fig. 7). This wall 46' and the wall 24 serve to prevent circulation or escape of heat and gases inwardly through the spout l6.

Means, generally indicated at 53, are provided for supplying air under pressure to the ash pit 4 below the grate 3, and into the spout l6 rearward of the wall 24, such 'supply'being in proportion to the speedof the motor 34 and feed of the material or fuel into the fire box. The supply means comprises a blower 54, preferably of the multi-blade type, suitably mounted in a casing 55, the shaft of the blower being connected to an extended end of the shaft of the motor 34, so that air is supplied only when the motor 34 is in operation. The casing 55 is provided with a main outlet 56 to which is connected one end of a flexible conduit 51, the opposite end thereof leadin into and through a draft opening formed in a door 6a for the opening 8; the latter end of the conduit being provided with a plate 58 to close the draft openin around the conduit. The plate 58 may be detachably connected to the ash pit door 8a.

The outlet 56 is provided with a valve 59, suitably trunnioned on an off-set axis to rock, the pressure of the supplied air maintaining valve 59 open when the blower is operating, but when the blower is stopped, a counterweight 59a closing the valve to prevent escape of gases from the ash pit, or flow of air thereinto by reason of any suction effect within the fire box.

The supply of air through the conduit 56 may be regulated by the following means: That end of the rock shaft for the valve 59 adjacent the counter-weight 59a rotates "in a tubular member 59!), which is threaded into a.hollow boss provided on the wall of the conduit. The member 59b is provided on its outer end with a collar, the outer sides of which are flat to form tool engaging surfaces. At one side the collar is cut away to receive the arm constituting the counters weight 5941, and one end wall of. the cut away portion of the collar forms a stop, which is engaged by the arm 59a to limit the swing of the valve 59 to the open position. Accordingly,

porting boss, the stop may be positioned to regulate or limit the swing of the valve 59. The tubular member 5% is held in its adjusted position by a set screw 59a.

The casing 55 also provided with a lateral chamber 60 connected with the casing 55 by an opening or 'port 60a, which is normally closed by a gravity operating valve 6| and opened by the pressure of the air when the blower is set in operation. The movement of the valve 6| is regulated by a set screw 62, to control the supply of air to the chamber 60. The inner side wall of the chamber 60 is formed with an opening into which the inner end of a pipe 63 fits, such pipe being held in position therein by a set screw 64. The pipe 63 extends outwardly, through the wall I lb andinto the adjacent space (see Fig. 4) between the walls of the spout and side wall 22a. The outer end of the pipe 63 is open and supplies air into the spout l6 to maintain its walls and those of the trough relatively cool and for another reason to be set forth later. Such supplied air may escape through openings 24:: formed in the spout wall We to the fire box for combustion purposes.

In Figures 13, 13a, 14 and 15 there is disclosed a modified form of construction. Here a spout 2 l6 similar to spout I6 is disclosed as containing a trough 222 corresponding to the trough 22 and a W-shaped member 223 similar to the member 23 and having outer walls 223a. and inner walls 223b. Walls 223a are provided with fuel retarding elements 233a which correspond essentially to the fuel retarding elements 330.. The inner walls 223!) support a reciprocatable member 23I provided with fuel feeding elements 233 corresponding to the feeding elements 33 of the previous modification. In the form shown in Figure 13 the reciprocatable member 23! takes the form of an inverted V and is positioned over the middle section of the W-shaped member 223. The central portions of walls 223!) are cut away at their outer ends as indicated at 2231) in such a manner that the outer end of a triangular hollow bar "H which is substantially similar to the bar 46 of the previous modification and operated by a motor similar to motor 34 through corresponding driving elements including a rod 249, may 'be connected through a spacer 12 to the reciprocatable member 23l. The cut away portion 2231) thus provides a space to accommodate spacer 12 upon reciprocatable motion of hollow bar II. The side walls 223a may extend to the outer end of the spout 2I6, the parts, bar 46, spacer 12 and the reciprocatable member 23l, may be spot-welded together to hold the same in related assembly. A hood 13, as better shown in Figure 13a, is positioned adjacent the rear or inner end of the reciprocatable member 23I and secured to a wall 22l corresponding to the wall 2| previously indicated, and overlies the reciprocatable member 23| to prevent dust or particles of fuel from lodging below or beyond the same. The opposite longitudinal side edges of the member 23! are provided with a plurality of serrations 23l formed by cutting laterally projecting faces into the side edges in order that any dust or small particles of fuel settling in the bottom of the channel out of the normal range of fuel feeding elements 233 may be fed forwardly into' the fire box 2. Thus it will be seen that in the foregoing modification there is provided a fuel feeding structure similar in many respects to that previously described, the primary distinction lying in the fact that whereas in the previous modification the outer walls of the fuel feedingmember were recipro-- cated by means of a reciprocatable bar, here the inner walls are moved by means of a corresponding reciprocatable bar.

Figs. 16 and 16a show a construction similar to Figs. 13, 13a, 14 and 15, but in which reciprocatable feed members 23l carry at their rear or of the preferred embodiment.

Figs. 17 and 17a show a construction in which the feed members are disposed adjacent to each other, as shown in Figs. 13 to 160, inclusive, but are disposed vertically and secured (as by spot-welding) to the opposite faces of a reciprocatable plate 16, which, near the outer end of a spout l6 corresponding to spout I6 is connected to a block 11, and operated similarly to the hollow bar 46. The rear. end portion of the plate 16 is provided with an agitator 14', similar to the agitator I4 shown in Figs. 16 and 1611. In this form of construction, the.outer sides 323a of the feed chanels 29, 30, are supported by the side walls of the spout l6 and. plates 18 resting on the bottom thereof.

Fig. 18 shows a construction in which a single feed channel 19 is provided in the spout. In this construction, one inclined side is provided with retarding elements 433a and the opposite or opposed inclined side 800. carries a reciprocatable feed member 8| provided with fuel advancing elements 433. Also, in this form of construction the operating bar, shown at 82 is mounted to reciprocate in the space below the wall 80a and is connected to the member 6|, by providing a spacer 8Ia between its inclined wall 32a and the member BI and spot-welding these parts together, the wall 80a. being cut away as at 60b to receive the spacer 8la and permitting it to reciprocate. The bar 82 is reciprocated similarly to the bar 46.

Combustion in the fire box may be maintained for an indefinite period of time due tothe supply of fuel and air by the feeding or staking mechanism, butpreferably the combustion and supply of heat and air is automatically controlled. In the arrangement shown in Fig. 12, I provide a suitable control responsive to temperature. changes in the area or areas to be heated, as such areas are affected by outside temperatures, whereby the feeding or stoking mechanism is operated and stopped in accordance with such temperature changes to maintain a substantially fixed temperature in such areas and a suitable control responsive to the conditionswithin the fire box (when outside temperature permits), whereby the feeding or stoking mechanism is operated and stopped in accordance with such fire boxtemperature changes to maintain a substantially inactive fire bed which serves as a pilot.

Referring to the control means diagrammatically shown in Fig. 12, the motor 34 is set in operation and stopped by a switch means '65 undercontrol of a thermostat 66, which is located tion, but is arranged to close a circuit upon the drop in temperature to that for which it is set and to break the circuit upon the rise of tem-- perature approximately one degree. When the temperature in the area remains above that degree for which the thermostat 88 is set to effect closing of the motor circuit the feed mechanism remains idle and permits the fire in the fire bed to gradually die down or drop, with a corresponding drop in temperature of. the gases or atmosphere in the fire chamber. To prevent extinguishment of the fire on the one hand and on the other hand to maintain sufiicient combustion in the fire bed to ignite fresh fuel in the event the thermostat 88, due. to drop in' the room temperature, operates the switch means 85, I provide for the automatic starting and stopping of the motor 84 to feed fuel to the fire box by a supplemental switch 81 (see Figs. 11, 11a) under the control of a thermostat 88, which extends through the outer space 25 in the spout I8 and beyond the wall 28, so that its outer end is exposed to the radiant heat in the fire box. The thermostat .88 preferably comprises an outer tube 88:: of copper (which has a relatively high co-efiicient of expansion) and an inner member, for example a rod 881) formed of carbon (which has a relatively low co-efiicient of expansion). The inner end of the tube 88a is fixedly mounted in the wall IIb and is closed at its outer end. The rod 88b normally bears against the closed outer end of the tube 88a and moves outwardly under the influence of a spring (later referred to) with such end when the tube expands, but is moved inwardly by such end when the tube contracts. At its inner end, the rod 88b is arranged to actuate a lever 88, which. in turn closes the switch 81 (as later set forth), these parts being so arranged that the switch 81 will close the circuit when the temperature in the fire box falls to or below approximately 150? F. and open the circuit when the temperature in the fire box rises to or above approximately 175, that is, so long as the temperature in the fire box is above 150", the tube 880 is pressed outwardly under the infiuenc of its spring, but if the combustion in the fire bed drops so that the temperature in the fire box falls to or below approximately 150 F., then the rod 88b will contract sufliciently to cause endwise movement of the rod 881), the effect of which is to close the switch 81 and set the motor 84 in operation, whereby fresh fuel and air will be supplied to the fire bed to maintain combustion therein. Upon rise in temperature of the atmos phere in the fire box to or above 175, the thermostat 88 will openthe motor circuit and effect stoppage of the motor. The switch 81 and thermostat 88 are inter-related to the switch means 85 and thermostat 88 for controlling it and so arranged and connected in the circuit for the motor 88 that the switch 81 automatically operates'when the thermostat 88 is inoperative or is ineffective when the temperature conditions are such as to bring the thermostat 88 into operation.

- The switch mechanism 88 is mounted in a casing 85' and the switch 81 is mounted in a casing 81' (see Figs. 2, 4, 11 and 11a).

The, thermostats 88 and 88 control the circuits for the motor 88 in the following manner: The supply mains are indicated at 88, 88a, and are connected by a double arm knife switch 85 through terminals 85a to leads 88, 84a. The lead 84a has interposed in it a safety switch, generally indicated at 88, to which reference will later be made, and extends to one side of the motor 38. From the other side of the motor is a lead 81 connected to one contact 88 of an electromagnetic switch 88, the other contact 88a of the switch being connectedto the lead 84, so that when the switch 88 is closed byenergization of the switch coil 88a against the tension of a spring 88', the circuit for the motor 34 is closed across the contacts 88, 88a, The coil 88a is energized and de-energized by the control of the following circuits by the thermostat 88.

Leads 88 connect the terminals 85a with terminals of the primary winding of a transformer 8|. The secondary winding of the transformer is connected to leads 82, 83. The thermostat 88 preferably comprises a bi-metal element 88' connected at its inner end to a main terminal 88. The free end of the bimetal element 88' is adapted, when the surrounding temperature is above that atwhich the adjustment member thereof is set, to engage a terminal 85 which is connected to the lead 88 and when the temperature falls below thepredetermined set degree, to engage a terminal 88, which is. connected to'the lead 82.

A lead 88 is connected to the lead 82 and a terminal I88 of a second switch arm I8I carried by switch 88 and opened and closed thereby simultaneously with the opening and closing respectively of the circuit across the terminals 88, 880, the other terminal of the switch arm I8I being connected by a lead I82 to a lead I83 which in turn is connected to the main terminal 8|. The lead I83 is connected by lead IN to one end of the winding 88a, the other end of the latter being connected by a lead I84 to the lead 88.

The switch 81 preferably comprises a mercury tube 81a, the contacts of which are connected by leads I85, I88, to the contacts 88, 88a, respectively, and serves to complete the circuit for the motor and set it in operation upon the drop of the temperature below that for whieh the thermostat 88 is set, as already set forth, with resulting feeding of the 'fuel to the combustion chamber or fire box. I

The switch means 85 and switch 81 .operate as follows: assuming that the main switch 85 is closed, the thermostat 88 is set to operate when the temperature in the room where it is located drops to 68 F. and that such temperature is higher. Under these conditions, bimetal element- 88' will be in contact with contact 85; If the temperature drops to 68 F. bimetal-element 88' will swing into engagement with the terminal 88.

This engagement completes a circuit'through.

Accordingly, if the bimetal element 85' disengages' the terminal 88 (due to rise in temperature) the circuit for the coil 88a will remain completed as follows: from one end of the secondary winding is to de-energize the latter, whereupon the motor circuit across terminals G8, 880., will be broken, thus stopping the motor 34 and the supplemental circuit through switch arm IOI will be opened, so that the circuits cannot again be completed until the thermo-element 06 again engages the terminal 96.

Referring to Figures 11 and 11a, mercury tube 61a is mounted in a cradle Ii'le, connected through a series of levers 61b, 61c, Bid, to a main lever 69, lever 61d being normally actuated in one direction by a spring 67 and operating through levers 61b, 61c, 61d and lever 69 to move rod 68b inwardly when tube 68a expands.

As better shown in Figure 11, a spring 611: is interposed between lever 69 and lever 61b and arranged to prevent undue stress on the component parts of the thermostat 68 in the event that a too high or too low temperature causes an over travel of rod 68b beyond the normal operating limits of the instrument. The resilient connection thus provided between lever 69 and lever heating medium; namely, air in the present disclosure, a leverage including a bell crank 86b and a mercury tube 860 the contacts of which are interposed in the lead from one side of the motor 34 (lead 84a in Fig. 12) e As shown, the tube 860 is normally maintained in that position which closes the circuit, but should the heating medium in the heating apparatus rise to an abnormal degree the bell crank 85a will be moved in a clockwise direction to swing the tube to its other position and thus break the motor circuit. Where the heating apparatus consists of a steam boiler the switch 86 would be of pressure type well known in the art and operate to open the circuit for motor 34 at a predetermined pressure below the safe operating pressure of the boiler.

Means, generally indicated at I4I, related to the outer end of the spout I 6 and in the path of the fuel as it is discharged therefrom are provided for distributing it over the grate or fire bed instead of allowing it to pile up in the form of a cone, the purpose being to maintain a fire bed in contact with the heat absorbing surfaces or walls of the fire box. The means I may be disposed below the spout but suspended therefrom, and arranged to divert the falling fuel toward opposite sides of the fire box. In the preferred'form of construction, I provide a device, supported centrally between its ends and provide means for rotating it, so that the fuel is engaged and impelled downwardly and outwardly in various directions, whereby a substantially uniform distribution of the fuel around the fire box results; also, I provide a device so constructed that the atmosphere in the fire box is stirred or mixed to insure turbulence and burning of the gases and the prevention of stratification. To effectively carry out these functions, the device comprises a section of pipe I40 open from end to end and formed on its lower side with an opening I4Ia. The pipe section is pivoted centrally to the lower end of a flexible element, such as a chain I42. The upper end of the chain is connected to a gear in a gear box I43 and the gear meshes with a worm on the outer end of a flexible shaft I 44. The inner end of the flexible shaft I44 is suitably geared to one end of the shaft 36a. The fuel in falling or discharging from the spout I6 is engaged by the rotating pipe section and diverted in lateral directions so that the fuel bed is built up in contact with the side walls of the fire box i and more or less distributed over the entire area of the box. Rotating pipe section I40 serves to agitate the gases and oxygen in the fire box by its passage therethrough. Likewise, the relatively rapid rotation of pipe I40 occasions through the centrifugal force thereby created an exodus of the gases adjacent the open ends thereof, such exodus reduces the pressure in the central portion of the pipe adjacent aperture I4Ia to create a slight suction suiiicient to draw a certain proportion of the gases in fire box 2 into opening I4Ia, which gases then escape through the open ends of pipe segment I40 in a lateral direction. This lateral diffusion of gases in the fire box plus the normal agitation occasioned by a rotated body therein results in circulation of the atmosphere, and the gases resulting from combustion become mixed with any free oxygen so that such gases are readily consumed in the fire box.

It will be noted that the thermostat 68 extends through the wall 24, so that the portion beyond the wall is exposed to the heat of the combustion chamber and the portion inwardly of the wall is exposed to the air supplied through pipe 63. The position of the wall 24 may be changed to expose a larger or smaller portion of the thermostat to the radiant heat from the combustion chamber; also, by adjustment of j the valve 6| the amount of air delivered into the spout I6 may be regulated to vary the responsive action of the thermostat 68, whereby itsrange of operation may be varied, that is, the difference in temperatures between the closing and opening of the switch 61 may be varied.

To those skilled in the art to which my invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the invention. My disclosures and the description herein are purely illustrative and not intended to be in any sense limiting.

What I claim is:

1. In a mechanism for feeding solid material into a chamber having an opening, the combination of a spout, means for supplying material, said spout extending through said opening and terminating in said chamber, a channel in said spout arranged to receive material from said supply means and comprising opposed walls one of which is inclined, one of said walls being arranged to reciprocate relative to the other wall. said reciprocatable wall being provided with material advancing elements and said other wall being provided with material retarding elements, and means for reciprocating said reciprocatable wall.

a 2. In a mechanism for feeding solid material into a chamber having an opening, the combination of a spout and a hopper mounted in connected relation, said spout extending throughv wall, an air supply pipe leading into said spout u between it and portions of said channel and means for reciprocating said reciprocatable wall and supplying air to said pipe.

3. In a mechanism for feeding solid materials into a chamber having an opening, the combination of a spout and a hopper mounted in connected relation, said spout extending through said opening and terminating in said chamber, a plate, W-shaped in cross section mounted in said spout and forming a pair of feed channels extending longitudinally of said spout arranged .to receive material from said hopper, a device -mounted on one wall of each channel and arranged to reciprocate longitudinally thereof, to feed the material through said channel, and means for reciprocating said devices.

4. In a mechanism for feeding solid material into a chamber having an opening, the combination of a spout and-a hopper mounted in connected relation, said spout extending through said opening and terminating in said chamber, a plate, w-shaped in cross section mounted in said spout and forming a pair of feed channels extending longitudinally of said spout arranged to receive material from said hopper, a device mounted on one wall of each channel and arranged to reciprocate longitudinally thereof, to

" feed the material through said channel, each said reciprocatable device being provided with material advancing elements and the other wall of the adjacent channel being provided with material retarding elements, and means for reciprocating said devices.

5. In a mechanism for feeding solid material into a chamber having an opening, the combination of a spout extending through said opening and terminating in said chamber, a hopper, a plate mounted in said spout and forming a feed channel arranged to receive material from said hopper, a device mounted on one wall of said channel and arranged to reciprocate longitudinally thereof, to feed the material through said channel, means for reciprocating said device,

.means projecting from the lower edge of said reciprocatable device for advancing the material, and means on another wall of said channel for retarding movement of said material, said wall remaining stationary.

6. In a mechanism for feeding solid material into a chamber having an opening, the combination of a spout and a hopper mounted in connected relation, said spout extending through said opening and terminating in said chamber,

a trough in said spout connected at its inner end a substantially U-shaped trough and spout, relatively movable devices in said trough arranged to receive material from said hopper and support and feed fuel therefrom for discharge into the fire box, a wall in said spout, an air supply pipe leading into said spout and terminating rearward of said wall, means for operating said movable devices and supplying air to said pipe, a themestat extending through said spout and having a portion beyond-said wall exposed to the radiant heat in the fire box, and a mechanism controlled by saidthermostat for starting and stopping said operating means.

8. In a fuel feeding mechanism, the combination with a heating apparatus having a combustion chamber and an opening therefor, of a spout leading through said opening, means for feeding fuel through said spout for discharge from the inner end thereof into said chamber, a device in the path of the fuel for directing it to different parts of the grate as'it falls from said spout for spreading the fuel on the grate or fire bed in. said chamber, and means for rotating said device, said device comprising a pipe suspended by said rotating means intermediate its-ends and formed with an opening on its lower side.

9. In apparatus of the class described, the combination with a furnace, of a spout extending into the combustion chamber of said furnace, a motor, means driven by said motor for feeding fuel through said spout, a passage for delivering air into said spout, means driven by said motor for supplying air to said passage, control means for said motor including a thermostat located in said spout, and a closure in said spout whereby a portion of said thermostat is shielded from the heat of said furnace and contacted by said supplied air. 1

10. An apparatus of the class described, the combination with a furnace, of a spout extending into the combustion chamber of said furnace, a

motor, means driven by said motor for feeding through said opening in the said fire box, means for feeding fuel through said spout into said fire box, a motor operating said feeding means, means driven by said motor for supplying air to said fire box and to said spout, and control means for said motor, said control means comprising a thermostat positioned in said spout and having a portion thereof shielded from said fire box responsive to the temperature of the air supplied to said spout.

12. In a fuel feeding mechanism for a heating apparatus having a fire box and an opening therefor, the combination of a spout extending through said opening into said fire box, means for feeding fuel from said spout into said fire box, a motor operating said feeding means, means driven by said motor for supplying air to said spout, means comprising a thermostat positioned in said spout for controlling said motor, and a partition in said spout through which said thermostat extends whereby a portion of said thermostat is exposed to the heat of said fire box and another portion thereof is exposed to said supplied air.

13. In a fuel feeding mechanism for a heating apparatus having a fire box and an opening therefor, the combination of a spout extending through said opening into said fire box, means for feeding fuel through said spout in the said fire box, a motor operating said feeding means, a partition in said spout below said feeding means, a motor for supplying air to said spout on the opposite side of said partition from said fire box, means comprising a thermostat positioned in said spout for controlling said motor, said thermostat extending through said partition whereby a portion of said thermostat is exposed to the heat of said fire box and another portion thereof is exposed'to said air supplied to said spout, and means for varying the position of said partition whereby the extent of said portion exposed to said fire box may be varied.

14. An apparatus of the class described comprising in combination, a furnace having a fire box, a spout extending into said fire box, a motor, means driven by said motor for feeding fuel through said spout, a passage for supplying air into said spout, means driven by said motor for supplying air to said passage, control means for said motor including a thermostat located in said spout having a portion thereof exposed to the heat of said fire box, and means associated with said thermostat to vary the temperature value to bustion chamber, a spout combustion chamber, a

which said thermostat responds, said last mentioned means comprising means for varying the area of the portion of said thermostat exposed to said fire box.

15. An apparatus of the class described comprising in combination, a furnace having a comextending into said motor, means driven by said motor for feeding fuel through said spout, a passage for delivering air into said spout, means driven by said motor for supplying air to said passage, control means for said motor including a thermostat positioned in said spout, a portion of said thermostat being responsive to the temperature of said combustion chamber and another portion being exposed to said delivered air, and means to vary the respective extent of said portions whereby to vary temperature value to which said thermostat responds, said means comprising a movable partition in said spout.

MERRILL G. BENJAMIN. 

